They are due to provide more detailed information on the attack method at the Black Hat USA conference this year.

To create the malicious charger, the researchers used a BeagleBoard barebones system that costs around $45. "This hardware was selected to demonstrate the ease with which innocent-looking, malicious USB chargers can be constructed,"wrote the researchers in their conference summary.

I think I am smarter. I charge my phones only through the USB port on the PC. The chargers are still in their original shrink wraps. If in emergency I need to use an external charger I use one for a vanilla voice and text message phone ( 4 20/ 4 years ago) with a mini-usb to micro-usb adapter.